Cooperative Fish and Wildlife Research Units Program: Minnesota
Education, Research and Technical Assistance for Managing Our Natural Resources


Sleugh, T., McCoy, C.M., Pattengill-Semmens, C.V. et al. 2023. Migratory behavior of aggregating male Tiger Grouper (Mycteroperca tigris) in Little Cayman, Cayman Islands. Environ Biol Fish 106, 1195–1206 (2023). https://doi.org/10.1007/s10641-023-01399-w

Abstract

Tiger Grouper (Mycteroperca tigris) form fish spawning aggregations (FSAs) around the winter full moons (typically January through April) in the central Caribbean. Males defend territories to attract mates in a lek-like reproductive strategy. Prior studies have documented rapid declines in populations with FSA associated fisheries. This study examines the migratory behavior and spatial ecology of adult male Tiger Grouper in Little Cayman, Cayman Islands, to better understand the localized impacts of aggregation fishing. As part of the Grouper Moon Project, we acoustically tagged ten spawning male Tiger Grouper at the western end of Little Cayman in February 2015. Using an array of hydrophones surrounding the island, we tracked the movements of the ten tagged fish over a 13-month period. We observed 3 migratory strategies: resident fish (n = 2) that live at the FSA site, neighboring fish (n = 5) that live within 4 km of the site, and commuter fish (n = 3) that travel over 4 km for spawning. Fish began aggregating two days before the full moon and typically left between ten and twelve days after the full moon, January through May. Regardless of migratory strategy, all tagged fish that returned to spawn in2015 after the February tagging effort came back to the west-end FSA. However, in January2016, one fish appeared to attend a different FSA closer to its presumed home territory. Unlike other larger-bodied grouper, it appears that Tiger Grouper establish multiple FSAs around Little Cayman, and males attend FSAs near their home territories. Protracted spawning seasons, FSA site infidelity, and putative FSA catchments should all be brought into management consideration to ensure sustainable fisheries for this important species.